Dianthus Pharmaceuticals (DNTH) shares fell 1.92% to close at $107.04 on Sept. 9, 2026, then shed another 1.4% in after-hours trading to $105.54, even as CEO Marino Garcia used the Citi Biopharma Back to School Summit to lay out an updated picture of the company's classeprubart pipeline and next-generation programs.
The company, which sits on $1.2 billion in cash providing a runway into 2030 with a current ratio of 26.1 and effectively zero debt-to-equity, has positioned claseprubart — a C1s inhibitor — as the lead candidate across several autoimmune indications.
In myasthenia gravis, Phase II MaGic data announced in September 2025 showed statistically significant separation on both QMG and MG-ADL scores within seven days. The Phase III EMERGE trial is now underway testing two dosing regimens — once every two weeks and once every four weeks — with top-line results expected in the second half of 2028. Garcia highlighted the speed of onset as a key differentiator in a space where biologics penetration remains below 20% and roughly 40% of patients on FcRN therapies discontinue treatment within 12 months.
For chronic inflammatory demyelinating polyneuropathy (CIDP), interim data from Part A of the CAPTIVATE trial, drawn from an initial 40-patient cohort, revealed that approximately 75% of patients switching from intravenous immunoglobulin are doing better on classeprubart. Part B targets 128 responders. Original enrollment expectations called for up to 256 patients in Part A, but current response rates suggest fewer than 200 may suffice. An update on revised enrollment is expected before year-end 2026.
Top-line Phase II results for multifocal motor neuropathy are slated for December 2026. The trial is over-enrolled at roughly 15 patients per arm versus the original plan of 12.
Garcia also described early-stage candidates DNTH212, a bifunctional fusion protein combining C1s and BAFF/APRIL inhibition, and DNTH312, a next-generation dual inhibitor. DNTH212 entered single-ascending-dose Phase I testing in healthy volunteers — with systemic lupus erythematosus as the first indication followed by Sjögren's syndrome and dermatomyositis — and a study update is expected by end of 2026, with multiple-ascending-dose studies planned for 2027. DNTH312 is targeted to reach Phase I readiness by the end of 2027.
On the competitive front, Garcia pointed to potency data he said distinguishes classeprubart from rival C1s inhibitors: the company states classeprubart is seven times more potent than Sanofi's riliprubart at IC90 and 38 times more potent than empasiprubart on the CH50 Wieslab assay. He also outlined a proposed dosing model drawing on the safety profile of Sanofi's approved cold-agglutinin disease drug ENJAYMO (sutimlimab) combined with the autoinjector design and monthly-dosing cadence of Sanofi/Regeneron's DUPIXENT.
ClassEprubart is formulated for delivery through a 27-gauge needle autoinjector in five to seven seconds and remains stable at room temperature for up to four weeks.
